Respiratory drive heterogeneity associated with systemic inflammation and vascular permeability in acute respiratory distress syndrome.

BACKGROUND: In acute respiratory distress syndrome (ARDS), respiratory drive often differs among patients with similar clinical characteristics. Readily observable factors like acid-base state, oxygenation, mechanics, and sedation depth do not fully explain drive heterogeneity. This study evaluated the relationship of systemic inflammation and vascular permeability markers with respiratory drive and clinical outcomes in ARDS. METHODS: ARDS patients enrolled in the multicenter EPVent-2 trial with requisite data and plasma biomarkers were included. Neuromuscular blockade recipients were excluded. Respiratory drive was measured as PES0.1, the change in esophageal pressure during the first 0.1 s of inspiratory effort. Plasma angiopoietin-2, interleukin-6, and interleukin-8 were measured concomitantly, and 60-day clinical outcomes evaluated. RESULTS: 54.8% of 124 included patients had detectable respiratory drive (PES0.1 range of 0-5.1 cm H2O). Angiopoietin-2 and interleukin-8, but not interleukin-6, were associated with respiratory drive independently of acid-base, oxygenation, respiratory mechanics, and sedation depth. Sedation depth was not significantly associated with PES0.1 in an unadjusted model, or after adjusting for mechanics and chemoreceptor input. However, upon adding angiopoietin-2, interleukin-6, or interleukin-8 to models, lighter sedation was significantly associated with higher PES0.1. Risk of death was less with moderate drive (PES0.1 of 0.5-2.9 cm H2O) compared to either lower drive (hazard ratio 1.58, 95% CI 0.82-3.05) or higher drive (2.63, 95% CI 1.21-5.70) (p = 0.049). CONCLUSIONS: Among patients with ARDS, systemic inflammatory and vascular permeability markers were independently associated with higher respiratory drive. The heterogeneous response of respiratory drive to varying sedation depth may be explained in part by differences in inflammation and vascular permeability.

How we use angiopoietin-2 in the diagnosis and management of vascular anomalies.

The diagnosis of vascular anomalies remains challenging due to significant clinical heterogeneity and uncertain etiology. Evaluation using biopsy and/or genetic testing for somatic variants is invasive, expensive, and prone to sampling error. There is great need for noninvasive and easily measured blood laboratory biomarkers that can aid not only in diagnosis, but also management of treatments for vascular anomalies. Angiopoietin-2, a circulating blood angiogenic factor, is highly elevated in patients with kaposiform hemangioendothelioma with Kasabach-Merritt phenomenon and kaposiform lymphangiomatosis. Here, we describe our clinical experience using serum angiopoietin-2 as a biomarker for diagnosis and monitoring response to treatment.

Plasma levels of VEGF-A and VCAM-1 as predictors of drug-induced hypertension in patients treated with VEGF pathway inhibitors.

AIMS: Hypertension is a common toxicity induced by vascular endothelial growth factor (VEGF) pathway inhibitors. There are no validated markers of hypertension induced by these drugs. METHODS: We previously discovered that cancer patients with lower plasma levels of angiopoietin-2, VCAM-1 and VEGF-A are at high risk of developing severe hypertension when treated with bevacizumab. This study aimed to validate the predictive value of these markers in pretreatment plasma samples of an additional cohort of 101 colorectal cancer patients treated with regorafenib. The levels of angiopoietin-2, VCAM-1 and VEGF-A were measured by enzyme-linked immunosorbent assay (ELISA). The association between proteins and grade ≥2 regorafenib-induced hypertension was performed by calculating the odds ratio (OR) from logistic regression. Using the optimal cut-point of each protein, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for hypertension were estimated. RESULTS: Lower levels of VCAM-1 (P = .015, OR = 3.11, 95% CI 1.27-8.08) and VEGF-A (P = .007, OR = 3.47, 95% CI 1.40-8.75) were associated with a higher risk of hypertension. Levels of angiopoietin-2 were not associated with hypertension. The multivariable model indicates an independent effect of VCAM-1 (P = .018, OR = 3.18, 95% CI 1.25-8.68) and VEGF-A (P = .008, OR = 3.77, 95% CI 1.44-10.21). The presence of low levels of both VCAM-1 and VEGF-A had an OR of 9.46 (95% CI 3.08-33.26, P = 1.70 × 10-4 ) for the risk of hypertension (sensitivity of 41.4%, specificity of 93.1%, PPV of 70.6% and NPV of 79.8%). CONCLUSIONS: This study confirmed the value of VCAM-1 and VEGF-A levels in predicting hypertension induced by regorafenib, another VEGF pathway inhibitor.

ACE2 and ANGII levels in patients with COVID-19 based on thoracic tomography findings and PCR test results.

INTRODUCTION: Reverse transcriptase polymerase chain reaction tests and thoracic tomography have been widely employed in the diagnosis of the disease, but doubts about their sensitivity still persist. Also there are controversial results about ACE2 and AngII levels according to the severity of disease. In this study, we aimed to analyze the ACE2 and AngII levels in patients with suspected COVID-19 based on polymerase chain reaction test results and thoracic tomography findings and to examine their relationship with disease severity. METHODOLOGY: Patients with suspected COVID-19 in the emergency department were divided into 4 groups according to thoracic tomography findings and PCR test results. The in-hospital mortality of patients was recorded. ACE2 and AngII levels in patients were analyzed according to groups and severity of the disease. RESULTS: ACE2 levels for the patients with suspected COVID-19 were significantly lower than in the control group, but AngII levels were higher (not statistically significant). The mean age and male sex ratio of patients who developed acute respiratory distress syndrome (ARDS) and died were significantly higher than those who survived. Whereas there was no difference in ACE2 levels in patients with severe diseases such as ARDS and mortality, their AngII levels were significantly lower. CONCLUSIONS: It can be suggested that decreased ACE2 levels combined with increased AngII levels are determinative at disease onset and in the development of lung damage. However, decreased AngII levels are more determinative in patients with severe diseases such as ARDS and mortality.

Angiopoietin-2/-1 ratios and MMP-3 levels as an early warning sign for the presence of giant cell arteritis in patients with polymyalgia rheumatica.

BACKGROUND: Diagnosing patients with giant cell arteritis (GCA) remains difficult. Due to its non-specific symptoms, it is challenging to identify GCA in patients presenting with symptoms of polymyalgia rheumatica (PMR), which is a more common disease. Also, commonly used acute-phase markers CRP and ESR fail to discriminate GCA patients from PMR and (infectious) mimicry patients. Therefore, we investigated biomarkers reflecting vessel wall inflammation for their utility in the accurate diagnosis of GCA in two international cohorts. METHODS: Treatment-naïve GCA patients participated in the Aarhus AGP cohort (N = 52) and the Groningen GPS cohort (N = 48). The AGP and GPS biomarker levels and symptoms were compared to patients presenting phenotypically as isolated PMR, infectious mimicry controls and healthy controls (HCs). Serum/plasma levels of 12 biomarkers were measured by ELISA or Luminex. RESULTS: In both the AGP and the GPS cohort, we found that weight loss, elevated erythrocyte sedimentation rate (ESR) and higher angiopoietin-2/-1 ratios but lower matrix metalloproteinase (MMP)-3 levels identify concomitant GCA in PMR patients. In addition, we confirmed that elevated platelet counts are characteristic of GCA but not of GCA mimicry controls and that low MMP-3 and proteinase 3 (PR3) levels may help to discriminate GCA from infections. CONCLUSION: This study, performed in two independent international cohorts, consistently shows the potential of angiopoietin-2/-1 ratios and MMP-3 levels to identify GCA in patients presenting with PMR. These biomarkers may be used to select which PMR patients require further diagnostic workup. Platelet counts may be used to discriminate GCA from GCA look-alike patients.

Serum HGF and APN2 are associated with disability worsening in SPMS.

There are no reliable biomarkers that predict disability worsening in progressive Multiple Sclerosis (MS). We analyzed circulating biomarkers of hypoxia and angiogenesis in people with Secondary Progressive MS (SPMS) who participated in a clinical trial and were monitored prospectively for disability worsening. Concentrations of glucose transporter-1 (Glut-1), a marker of hypoxia, were higher in SPMS compared to controls. Moreover, low levels of angiopoietin-2 (APN2) and hepatocyte growth factor (HGF) were associated with disability worsening, while neurofilament light, an emerging biomarker in MS, was not. APN2 and HGF are neurotrophic and could be both potential biomarkers and therapeutic targets in SPMS.

Plasma ratio of angiopoietin-2 to angiopoietin-1 is a biomarker of vascular impairment in chronic obstructive pulmonary disease patients.

Chronic obstructive pulmonary disease (COPD) patients have an increased risk of cardiovascular disease. Muscle biopsies have revealed that the muscle vasculature in COPD patients was characterized by a capillary rarefaction with reduced pericyte coverage. Thus, an imbalance of the plasma Angiopoietin-1 / Angiopoietin-2 (Ang2/Ang1) ratio could constitute a non-invasive marker of the muscle vascular impairment. In 14 COPD patients (65.5±5.1-year-old) and 7 HC (63.3±5.8-year-old), plasma samples were obtained at 3 time-points: before, after 5 weeks (W5), and after 10 weeks (W10) of exercise training. COPD patients showed a muscle capillary rarefaction at baseline with a reduced capillary coverage at W5 and W10. The plasma Ang2/Ang1 ratio was significantly higher in COPD patients vs. HC during the training (Group: p=0.01). The plasma Ang2/Ang1 ratio was inversely correlated with the pericyte coverage index regardless of the time period W0 (r=-0.51; p=0.02), W5 (r=-0.48; p=0.04), and W10 (r=-0.61; p<0.01). Last, in ECFC/MSC co-cultures exposed to the W10 serum from COPD patients and HC, the plasma Ang2/Ang1 at W10 were inversely correlated with calponin staining (r=-0.64. p=0.01 and r= 0.71. p<0.01, Fig. 1B), in line with a role of this plasma Ang2/Ang1 in the MSC differentiation into pericytes. Altogether, plasma Ang2/Ang1 ratio could constitute a potential marker of the vascular impairment in COPD patients.

Association of Pre-Transplant Angiopoietin-2 Index with the Risk of Acute Graft-Versus-Host Disease after Hematopoietic Stem Cell Transplantation

Objective: Angiogenic factors (AFs) released under endothelial stress are reflective of tissue healing, while some may also contribute to tissue damage/inflammation. We investigated whether alterations in the pre-transplant levels of AFs were associated with the risk of acute graft-versus-host disease (aGvHD). Materials and Methods: The pre-conditioning plasma levels of angiopoietin-2 (Ang2), endoglin, and follistatin were measured for 37 patients together with inflammatory markers. The index values defined were evaluated to better identify the alterations. Results: The patients had higher pre-conditioning levels of Ang2, endoglin, and follistatin compared to controls. The patients with aGvHD had higher Ang2 index and lower albumin index scores in comparison to those without aGvHD. Multivariate analysis revealed that the pre-transplant Ang2 index was an independent risk factor for aGvHD development. Conclusion: Pre-transplant evaluation of plasma Ang2 levels along with inflammatory status even before conditioning is associated with endothelial vulnerability. The pre-transplant Ang2 index could be a promising candidate to estimate the risk of aGvHD.

Biomarker Analysis for Combination Therapy of Vitamin C and Thiamine in Septic Shock: A Post-Hoc Study of the ATESS Trial.

INTRODUCTION: We evaluated the effects of vitamin C and thiamine administration on biomarkers in patients with septic shock. METHODS: This was a post-hoc analysis of the Ascorbic Acid and Thiamine Effect in Septic Shock (ATESS) trial, a multicenter, double-blind, randomized controlled trial. Patients were randomized to either a treatment group (intravenous vitamin C and thiamine for 48 h) or a control group. Interleukin (IL)-6, IL-10, angiopoietin-II (AP2), and S100ß were assessed at baseline and at 72 h. The primary outcomes were the biomarker levels at 72 h, and the secondary outcome was reduction rate. RESULTS: Forty-five patients were assigned to the treatment group and 52 were assigned to the control group. Baseline biomarker levels and at 72 h were not significantly different between the treatment and the placebo groups. The reduction rates were not significantly different between the two groups. These outcome variables showed fair diagnostic accuracy for predicting 28-day mortality according to the area under the receiver operating characteristic curve. CONCLUSION: Vitamin C and thiamine administration during the early phase of septic shock did not significantly change prognostic biomarker levels of IL-6, IL-10, AP2, and S100ß. TRIAL REGISTRATION: NCT, ClinicalTrials.gov NCT03756220, ATESS. Registered 28 November 2018, https://clinicaltrials.gov/ct2/show/NCT03756220.

Clinical and biological markers for predicting ARDS and outcome in septic patients.

Sepsis is a common cause of acute respiratory distress syndrome (ARDS) associated with a high mortality. A panel of biomarkers (BMs) to identify septic patients at risk for developing ARDS, or at high risk of death, would be of interest for selecting patients for therapeutic trials, which could improve ARDS diagnosis and treatment, and survival chances in sepsis and ARDS. We measured nine protein BMs by ELISA in serum from 232 adult septic patients at diagnosis (152 required invasive mechanical ventilation and 72 had ARDS). A panel including the BMs RAGE, CXCL16 and Ang-2, plus PaO2/FiO2, was good in predicting ARDS (area under the curve = 0.88 in total septic patients). Best performing panels for ICU death are related to the presence of ARDS, need for invasive mechanical ventilation, and pulmonary/extrapulmonary origin of sepsis. In all cases, the use of BMs improved the prediction by clinical markers. Our study confirms the relevance of RAGE, Ang-2, IL-1RA and SP-D, and is novel supporting the inclusion of CXCL16, in BMs panels for predicting ARDS diagnosis and ARDS and sepsis outcome.

Construction and validation of risk prediction model for deep vein thrombosis in acute exacerbations of chronic obstructive pulmonary disease based on serum angiopoietin 2 levels.

BACKGROUND: This study aims to establish a predictive risk model for deep vein thrombosis (DVT) in patients with acute exacerbation chronic obstructive pulmonary disease (AECOPD) based on serum angiopoietin 2 (Ang-2) levels. METHODS: The research sample consisted of 650 patients with AECOPD admitted to the First Affiliated Hospital of Chengdu Medical College from January 2019 to January 2021, who were subsequently divided into a modeling group and a verification group. A univariate analysis was performed on the identified risk factors for DVT in AECOPD, and the significant factors were then incorporated into a multivariate logistic regression model to screen for the independent predictors of DVT. A nomogram was constructed, and a receiver operating characteristic curve (ROC), Hosmer-Lemeshow test, decision curve, and clinical impact curve in the modeling and validation cohort were used to analyze the discrimination power, calibration, and clinical validity of the predictive risk nomogram model of AECOPD with comorbid DVT. RESULTS: Univariate and multivariate logistic regression analyses showed that lower limb edema, BMI, diabetes, respiratory failure, D-dimer, and serum Ang-2 were risk factors for DVT in AECOPD. A nomogram model for predicting AECOPD with comorbid DVT was successfully established. The AUC values for the modeling group and the verification group were 0.844 (95% CI: 0.808-0.932) and 0.755 (95% CI: 0.679-0.861), respectively. According to the Hosmer-Lemeshow test, the P values of the nomogram in the modeling group and the verification group were 0.124 and 0.086, respectively. The decision curve and clinical impact curve suggested that most patients can benefit from this prediction model, and the predicted probability of the model was essentially the same as the actual clinical probability of DVT. CONCLUSIONS: The predictive risk nomogram model of AECOPD with comorbid DVT based on serum Ang-2 levels has good discrimination power, calibration, and clinical influence. The model is a good fit and has a high predictive value, which helps clinicians identify AECOPD patients at high risk of DTV and formulate corresponding prevention and treatment measures.

Angiopoietin-2 and angiopoietin-like 4 protein provide prognostic information in patients with suspected acute coronary syndrome.

BACKGROUND: Plasma levels of angiopoietin-2 (ANGPT2) and angiopoietin-like 4 protein (ANGPTL4) reflect different pathophysiological aspects of cardiovascular disease. We evaluated their association with outcome in a hospitalized Norwegian patient cohort (n = 871) with suspected acute coronary syndrome (ACS) and validated our results in a similar Argentinean cohort (n = 982). METHODS: A cox regression model, adjusting for traditional cardiovascular risk factors, was fitted for ANGPT2 and ANGPTL4, respectively, with all-cause mortality and cardiac death within 24 months and all-cause mortality within 60 months as the dependent variables. RESULTS: At 24 months follow-up, 138 (15.8%) of the Norwegian and 119 (12.1%) of the Argentinian cohort had died, of which 86 and 66 deaths, respectively, were classified as cardiac. At 60 months, a total of 259 (29.7%) and 173 (17.6%) patients, respectively, had died. ANGPT2 was independently associated with all-cause mortality in both cohorts at 24 months [hazard ratio (HR) 1.27 (95% confidence interval (CI), 1.08-1.50) for Norway, and HR 1.57 (95% CI, 1.27-1.95) for Argentina], with similar results at 60 months [HR 1.19 (95% CI, 1.05-1.35) (Norway), and HR 1.56 (95% CI, 1.30-1.88) (Argentina)], and was also significantly associated with cardiac death [HR 1.51 (95% CI, 1.14-2.00)], in the Argentinean population. ANGPTL4 was significantly associated with all-cause mortality in the Argentinean cohort at 24 months [HR 1.39 (95% CI, 1.15-1.68)] and at 60 months [HR 1.43 (95% CI, 1.23-1.67)], enforcing trends in the Norwegian population. CONCLUSIONS: ANGPT2 and ANGPTL4 were significantly associated with outcome in similar ACS patient cohorts recruited on two continents. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00521976. ClinicalTrials.gov Identifier: NCT01377402.

Diagnostic and prognostic significance of serum angiopoietin-1 and -2 concentrations in patients with pulmonary hypertension.

Several biomarkers for detecting pulmonary hypertension (PH) have been reported. However, these biomarkers are deemed insufficient to detect PH in its early stages. We evaluated the utility of serum angiopoietin (ANGP), a glycoprotein related to angiogenesis, as a diagnostic and prognostic biomarker of PH. Patients with PH who underwent right-heart catheterization, were retrospectively studied. Serum concentrations of ANGP-1 and ANGP-2 were measured using an enzyme-linked immunosorbent assay in patients with PH (n = 32), those with idiopathic pulmonary fibrosis (IPF) without PH (as a disease control, n = 75), and age-matched healthy controls (HC, n = 60). Nineteen patients (59.4%) with PH had World Health Organization group 3 PH. Serum ANGP-2 concentration, but not ANGP-1, in patients with PH was significantly higher compared with that in HC (p = 0.025) and in patients with IPF without PH (p = 0.008). Serum ANGP-2 concentration in patients with PH positively and significantly correlated with N-terminal pro-B-type natriuretic peptide (r = 0.769, p < 0.001), right ventricular diameter on echocardiography (r = 0.565, p = 0.035), and mean pulmonary arterial pressure (r = 0.449, p = 0.032) and pulmonary vascular resistance (r = 0.451, p = 0.031) on right-heart catheterization. ANGP-1 and ANGP-2 were expressed on lung vascular endothelial cells, as shown by immunohistochemistry. Patients with PH with higher ANGP-2 concentration (≥ 2.48 ng/mL) had significantly worse survival (p = 0.022). Higher ANGP-2 concentration was a significant worse prognostic factor (hazard ratio = 6.063, p = 0.037), while serum ANGP-1 concentration was not. In conclusion, serum ANGP-2 may be a useful diagnostic and prognostic biomarker in patients with PH, especially in patients with group 3 PH.

Endothelial Dysfunction as a Component of Severe Acute Respiratory Syndrome Coronavirus 2-Related Multisystem Inflammatory Syndrome in Children With Shock.

TRIAL REGISTRATION: NCT04420468. OBJECTIVES: Severe acute respiratory syndrome coronavirus 2-related multisystem inflammatory syndrome in children is frequently associated with shock; endothelial involvement may be one of the underlying mechanisms. We sought to describe endothelial dysfunction during multisystem inflammatory syndrome in children with shock and then assess the relationship between the degree of endothelial involvement and the severity of shock. DESIGN: Observational study. SETTING: A PICU in a tertiary hospital. PATIENTS: Patients aged under 18 (n = 28) with severe acute respiratory syndrome coronavirus 2-related multisystem inflammatory syndrome in children and shock, according to the Centers for Disease Control and Prevention criteria. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Correlations between endothelial marker levels and shock severity were assessed using Spearman coefficient. The median (interquartile range) age was 9 years (7.5-11.2 yr). Sixteen children presented with cardiogenic and distributive shock, 10 presented with cardiogenic shock only, and two presented with distributive shock only. The median left ventricular ejection fraction, troponin level, and lactate level were, respectively, 40% (35-45%), 261 ng/mL (131-390 ng/mL), and 3.2 mmol/L (2-4.2 mmol/L). Twenty-five children received inotropes and/or vasopressors; the median Vasoactive and Inotropic Score was 8 (5-28). Plasma levels of angiopoietin-2 (6,426 pg/mL [2,814-11,836 pg/mL]), sE-selectin (130,405 pg/mL [92,987-192,499 pg/mL]), von Willebrand factor antigen (344% [288-378%]), and the angiopoietin-2/angiopoietin-1 ratio (1.111 [0.472-1.524]) were elevated and significantly correlated with the Vasoactive and Inotropic Score (r = 0.45, p = 0.016; r = 0.53, p = 0.04; r = 0.46, p = 0.013; and r = 0.46, p = 0.012, respectively). CONCLUSIONS: Endothelial dysfunction is associated with severe acute respiratory syndrome coronavirus 2-related multisystem inflammatory syndrome in children with shock and may constitute one of the underlying mechanisms.

Relationship between markers of inflammation and hemodynamic stress and death in patients with out-of-hospital cardiac arrest.

Biomarkers that reflect hemodynamic stress, inflammation, extracellular matrix remodeling, angiogenesis, and endothelial dysfunction may improve risk stratification and add valuable pathobiological insight in patients with out-of-hospital cardiac arrest (OHCA). In total, 120 patients with OHCA who survived at least 48 h after return of spontaneous circulation were consecutively included in the present analysis. Concentrations of 30 biomarkers were measured simultaneously using a multi-panel biomarker assay. Cox regression models were adjusted for age, sex, estimated glomerular filtration rate, lactate concentration, bystander resuscitation, initial cardiac rhythm, and type of targeted temperature management. Overall, 57 patients (47.5%) had a favorable neurological outcome (Cerebral Performance Category ≤ 2) at 30 days, while palliative care was initiated in 49 patients (40.8%), and 52 patients (43.3%) died. After correction for multiple testing with Bonferroni-Holm, 8 biomarkers (including Angiopoietin-2, Procalcitonin, Resistin, IL-4Rα, MMP-8, TNFα, Renin, and IL-1α) were significantly associated with all-cause death. After multivariable adjustment, only angiopoietin-2 (Adjusted (Adj) hazard ratio (HR) per 1-unit increase in standardized biomarker concentrations 1.52 (95% CI 1.16-1.99)) and renin (Adj HR 1.32 (95% CI 1.06-1.65) remained independently associated with an increased risk of death. The discriminatory performance indicated good performance for angiopoietin-2 (area under the curve (AUC): 0.75 (95% CI 0.66-0.75) and was significantly higher (P = 0.011) as compared with renin (AUC: 0.60, 95% CI 0.50-0.60). In conclusion, angiopoietin-2 was significantly associated with all-cause mortality in patients with OHCA who survived the first 48 h and may prove to be useful for risk stratification of these patients.

Role of angiopoietin-2 in venous thrombus resolution and chronic thromboembolic disease.

BACKGROUND: Defective angiogenesis, incomplete thrombus revascularisation and fibrosis are considered critical pathomechanisms of chronic thromboembolic pulmonary hypertension (CTEPH) after pulmonary embolism. Angiopoietin-2 (ANGPT2) has been shown to regulate angiogenesis, but its importance for thrombus resolution and remodelling is unknown. METHODS: ANGPT2 plasma concentrations were measured in patients with CTEPH (n=68) and acute pulmonary embolism (n=84). Tissue removed during pulmonary endarterectomy (PEA) for CTEPH was analysed (immuno)histologically. A mouse model of inferior vena cava ligation was used to study the kinetics of venous thrombus resolution in wild-type mice receiving recombinant ANGPT2 via osmotic pumps, and in transgenic mice overexpressing ANGPT2 in endothelial cells. RESULTS: Circulating ANGPT2 levels were higher in CTEPH patients compared to patients with idiopathic pulmonary arterial hypertension and healthy controls, and decreased after PEA. Plasma ANGPT2 levels were elevated in patients with pulmonary embolism and diagnosis of CTEPH during follow-up. Histological analysis of PEA specimens confirmed increased ANGPT2 expression, and low levels of phosphorylated TIE2 were observed in regions with early-organised pulmonary thrombi, myofibroblasts and fibrosis. Microarray and high-resolution microscopy analysis could localise ANGPT2 overexpression to endothelial cells, and hypoxia and transforming growth factor-ß1 were identified as potential stimuli. Gain-of-function experiments in mice demonstrated that exogenous ANGPT2 administration and transgenic endothelial ANGPT2 overexpression resulted in delayed venous thrombus resolution, and thrombi were characterised by lower TIE2 phosphorylation and fewer microvessels. CONCLUSION: Our findings suggest that ANGPT2 delays venous thrombus resolution and that overexpression of ANGPT2 contributes to thrombofibrosis and may thus support the transition from pulmonary embolism to CTEPH.

Utility of serum neuropilin-1 and angiopoietin-2 as markers of hepatocellular carcinoma.

This study aimed to assess the diagnostic value of two serum angiogenetic markers neuropilin-1 (NRP-1) and angiopoietin-2 (ANG-2) in patients with hepatocellular carcinoma (HCC) and their relation to tumor characteristics. 149 subjects were recruited and divided into 50 patients with recently diagnosed HCC, 49 patients with cirrhosis on top of hepatitis C virus infection, and 50 healthy subjects. Serum NRP-1 and ANG-2 were estimated by ELISA. Alpha-fetoprotein (AFP) levels were measured using fluorescence immunoassay. Serum NRP-1 and ANG-2 levels were significantly higher in patients with HCC (2221.8±1056.6 pg/mL and 3018.5±841.4 pg/mL) than healthy subjects (219.3±61.8 pg/mL and 2007.7±904.8 pg/mL) and patients with cirrhosis (1108.9±526.6 pg/mL and 2179.1±599.2 pg/mL), respectively. In multivariate logistic regression analysis, NRP-1 and AFP were the only independent factors of HCC development and correlated positively with each other (r=0.781, p<0.001). Receiver operating characteristic curve analysis showed that the area under the curve (AUC) of NRP-1 was higher than that of ANG-2 in discriminating HCC from patients with cirrhosis (0.801 vs 0.748, p=0.250) and healthy subjects (0.992 vs 0.809, p<0.001). The AUC of NRP-1 was detected to be increased (0.994) when combined estimation with AFP was performed. Elevated serum NRP-1 and ANG-2 levels were detected in patients with HCC with tumor numbers >3, tumor size ≥5 cm, tumor stages B/C according to the Barcelona Clinic Liver Cancer staging system, vascular invasion, and distant metastasis. In conclusion, NRP-1 is a potential serological marker for HCC diagnosis and is better than ANG-2. It is feasible to be estimated in combination with AFP to enhance its diagnostic power. High serum NRP-1 and ANG-2 levels are associated with advanced HCC tumor characteristics.

Repression of protocadherin 17 is correlated with elevated angiogenesis and hypoxia markers in female patients with breast cancer.

BACKGROUND: Altered cadherin expression plays a vital role in tumorigenesis, angiogenesis and tumor progression. However, the function of protocadherin 17 (PCDH17) in breast cancer remains unclear. OBJECTIVE: Our target is to explore PCDH17 gene expression in breast carcinoma tissues and its relation to serum angiopoietin-2 (Ang-2), carbonic anhydrase IX (CAIX) and % of circulating CD34+ cells in breast cancer patients (BCPs). METHODS: This study included Fifty female BCPs and 50 healthy females as control group. Cancerous and neighboring normal breast tissues were collected from BCPs as well as blood samples at diagnosis. PCDH17 gene expression was evaluated by RT-PCR. Serum Ang-2, CAIX levels were measured by ELISA and % CD34+ cells were assessed by flow cytometry. RESULTS: PCDH17 was downregulated in cancerous breast tissues and its repression was significantly correlated with advanced stage and larger tumor size. Low PCDH17 was significantly correlated with serum Ang-2, % CD34+ cells and serum CAIX levels. Serum CAIX, Ang-2 and % CD34+ cells levels were highly elevated in BCPs and significantly correlated with clinical stage. CONCLUSIONS: PCDH17 downregulation correlated significantly with increased angiogenic and hypoxia biomarkers. These results explore the role of PCDH17 as a tumor suppressor gene inhibiting tumor growth and proliferation.

Baseline elevated serum angiopoietin-2 predicts long-term non-regression of liver fibrosis after direct-acting antiviral therapy for hepatitis C.

We previously revealed that Angiopoietin-2 (Ang2) predicts non-regression of liver fibrosis based on liver stiffness measurement (LSM) at 24 weeks after anti-hepatitis C virus (HCV) treatment. In this study, we extended the observational period to 96 weeks to investigate the factors associated with non-regression after treatment with direct-acting-antivirals (DAAs). Patients treated with DAAs who underwent transient elastography at baseline and 24 and 96 weeks after DAA therapy were included. Baseline and post-treatment serum Ang2 levels were measured. Liver fibrosis stages were defined based on LSM. Multivariate regression was used to evaluate factors associated with non-regression of liver fibrosis between various time points. In total, 110 patients were included. Of these, 11% showed non-regression of LSM-based fibrosis stage at 96 weeks after DAA therapy. In multivariate analysis, advanced liver fibrosis stage and high baseline Ang2 levels were significantly associated with non-regression at 96 weeks. In patients with advanced liver fibrosis (F3/4), baseline Ang2 levels were associated with non-regression of liver fibrosis stage. Between SVR24 and SVR96, post-treatment Ang2 levels and controlled attenuation parameter values at SVR24 were significantly associated with non-regression of liver fibrosis stage in patients with F3/4. Thus, serum Ang2 levels are an important target for monitoring and therapy.